| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a drive system that optimizes expansion and contraction of the piezoelectric element in a piezoelectric actuator. <P>SOLUTION: A drive system includes a piezoelectric element 2 having a detection electrode 11 in which charges are induced according to expansion and contraction, a drive shaft having one end fixed to the piezoelectric element 2, a moving member friction engaging with the drive shaft, a drive circuit 6 that applies a periodic drive voltage to the piezoelectric element 2, a detection circuit 7 which determines the fundamental frequency component and the second harmonic component of variation in the induction charges Q of the detection electrode 11, and a controller 8 for changing the waveform of the drive voltage by controlling the drive circuit 6 according to the fundamental frequency component and the second harmonic component of the induction charges Q. <P>COPYRIGHT: (C)2010,JPO&INPIT |
